Gas turbine power plant control apparatus having improved monitoring and alarm elements

ABSTRACT

A gas turbine power plant is provided with an industrial gas turbine which drives a generator coupled to a power system through a breaker. The turbine-generator plant is operated by a hybrid control system having digital function capability during sequenced startup, synchronizing, load buildup and steady state load, and shutdown operations. The control system also contains monitoring and protective subsystems which function through all stages of operation, with redundancy and permissive features which maximize turbine availability.

United States Patent Yannone et a]. July 1, 1975 [54] GAS TURBINE POWER PLANT CONTROL 3,382,67l 5/i968 Ehni r. 290/38 APPARATUS HAVING IMPROVED 3,446,224 5/l969 Zwicky 290/40 3,533,236 l/l970 Cottington 290/40 MONITORING AND ALARM ELEMENTS inventors: Robert A. Yannone, Aldan; James J.

Shields, Philadelphia, both of Pa.

Primary ExaminerG. R. Simmons Attorney, Agent, or Firm-S. A. Seinberg [73] Assignee: Westinghouse Electric Corp.,

Pittsburgh, Pa. 57] ABSTRACT 22 F'l d: 20, l 73 I 1 June 9 A gas turbine power plant is provided with an indus- [21] Appl. No.: 371,630 trial gas turbine which drives a generator coupled to a power system through a breaker. The turbine- [52] U S 0 290/40. 60,39 235/151 21 generator plant is operated by a hybrid control system [51] F026 M having digital function capability during sequenced [58] Field 60/39 startup, synchronizing, load buildup and steady state 35 5 load, and shutdown operations. The control system also contains monitoring and protective subsystems [56] References cued which function through all stages of operation, with redundancy and permissive features which maximize UNlTED STATES PATENTS mrbine availability 3,243,596 3/1966 Loft 290/40 3,340,883 9/1967 Peternel 290/40 10 Claims, 39 Drawing Figures n H 25o PABK,- PZC/ HPZC) 2 R P I BASE za 5 I 203 EXHAUST Exn TEMP, THERMOCOUPLES zr CONTROL T p (lkOlAIOdd 267 A 52X p AND K/ T269 I'PARY AMBIENT owmm TEMP e/P TEMP, SENSORS CONTROL T23| iC/p 253 (STARTING al-w '258 TRANSIENT] K .J 8/? s ADE PAT I rttnmocouztes Accu. Low

Z /p 20 SIGNAL- SPEED LOAD SELECT zc LOAD (L55) lB/V TOTAL RATE zos SPEED s ree LOAD CHANGER 5 CONTROLLER ass j EL- isen i V c HZ;P FR ss-m I a i i L r 1 FAQ mam ,VLHMAL r z I-v'TrII I I I 1})8 T 7g. [48 I R TIMER MANUAL COUNTER AT ONE RE TI RESET M SHUTDOWN COUNTER OR COUNTER AT ZERO CONDITIONS MASTER A I CONTROL (4Y1) LOCKOUT SIGNAL MIN LSX TWO-SHOT BASE OR RESTART a TI PEAK A (RZX) LIJ 3 LL] 0. U)

2 TIME w NOT N I. T'IgJ4D ,3 T" ,I4C

S I TEI I I975 1,892,975

SHEET 9 zc 234 /225G 233 GAS I GAS ToTALIzER ETGSA L l T 2II H l I: IoIw 22I .2 I NR 1 T SUPPLY 2Io Y 225 f LSS- PR l' 1 I I I OIL I 235 HLR 206 PZC ToTALIzER I I R0 236 -E'S FUEL oIL PUMP M CONT- T0 FUEL oIL DISCHARGE PRESSURE T p G CO PRESSURE REGIvALvE F lg. 8A

F lg. 88

FUEL OIL OIL To COMBUSTION I T T.v. SYSTEM 7 9 \F z PRESSURE REG. 4 CONT. VALVE l l l --LSS LTRANSFER I SWITCH I I24 L GAS FUEL GAS \TO COMBUSTION v T.v. SYSTEM GAS STARTING VALVE GAS STARTING f 8| SIGNAL 

1. A gas turbine electric power plant comprising a gas turbine having compressor, combustion and turbine elements, a generator driven by said gas turbine, a fuel system for supplying fuel to said gas turbine combustion element, a control system having a plurality of control paths with inputs constantly connected to predetermined elements of said turbine and said generator, the output of said control system being connected to and continuously providing an output signal for operating said fuel system to energize said turbine, said control paths including a first plurality of primary control paths for developing a primary control signal for operating said fuel system during turbine startup, load and shutdown operations, and a second plurality of control paths for developing temperature backup control signals, each said backup control signal being a predetermined function of the temperature of a respective one of said turbine elements and at least one other turbine operating condition, said control system including means for selecting one of said backup signals as said control system output under predetermined turbine conditions, and means for continuously indicating which of said control paths is generating said selected signal.
 2. The gas turbine electric power plant as set forth in claim 1, wherein said control paths include a speed control path for control of turbine startup, a load control path for control of turbine load, a rate control path for limiting the rate of load increase, and at least two temperature backup control paths, and said selecting means is adapted to select the lowest signal generated by said control paths.
 3. The gas turbine electric power plant as set forth in claim 2, wherein said speed control path contains a plurality of input subpaths each of which provides an input signal representative of turbine speed, means for selecting one of said input speed signals, and means for determining and displaying relative differences of said input speed signals.
 4. The gas turbine electric power plant as set forth in claim 3, wherein there are two of said input subpaths, and said display means indicates when said input speed signals differ by more than 5%.
 5. The gas turbine electric power plant as set forth in claim 2, wherein each of said temperature backup control paths contains a plurality of input subpaths each of which provides an input temperature signal representative of temperature at a given turbine location, means for selecting one of said input temperature signals, and means for determining and displaying relative differences of said input temperature signals.
 6. The gas turbine electric power plant a set forth in claim 5, wherein there are two of said input subpaths, and said display means indicates when said input temperature signals differ by more than 5%.
 7. A gas turbine electric power plant comprising a gas turbine having compressor, combustion and turbine elements, a generator driven by said gas turbine, a fuel system for supplying fuel to said gas turbine combustion element, a control system having a plurality of control paths with inputs constantly connected to predetermined elements of said turbine and said generator, the output of said control system being connected to and continuously providing an output signal for operating said fuel system to energize said turbine, said control paths including a first plurality of primary control paths for developing a primary control signal for operating said fuel system durIng turbine startup, load and shutdown operations, and a second plurality of control paths for developing temperature backup control signals, each said backup control signal being a predetermined function of the temperature of a respective one of said turbine elements and at least one other turbine operating condition, each said backup control path including a pair of input subpaths each of which provides an input temperature signal representative of said respective turbine portion and means for displaying relative differences of said input temperature signals, said control system including means for selecting one of said backup signals as said control system output under predetermined turbine conditions, and means for continuously indicating which of said control paths is generating said selected signal.
 8. The gas turbine electric power plant as set forth in claim 7, wherein said control paths include a speed control path for control of turbine startup, a load control path for control of turbine load, a rate control path for limiting the rate of load increase, and at least two temperature backup control paths, and said selecting means is adapted to select the lowest signal generated by said control paths.
 9. The gas turbine electric power plant a set forth in claim 8, wherein said speed control path contains a plurality of input subpaths each of which provides an input signal representative of turbine speed, means for selecting one of said input speed signals, and means for determining and displaying relative differences of said input speed signals.
 10. The gas turbine electric power plant as set forth in claim 9, wherein each of said control paths generates a pneumatic signal so that said control system output is pneumatic, and said fuel system has a pneumatically operated valve for controlling the supply of fuel, said pneumatic control system output directly operating said valve. 